A blend of low-octane (light and heavy naphtha) and high-octane (reformate) distillate fuels has been proposed for powering gasoline compression ignition (GCI) engines. The formulated ‘GCI blend’ has a research octane number (RON) of 77 and a motor octane number (MON) of 73.9. In addition to ∼64 mole% paraffinic components, the blend contains ∼20 mole% aromatics and ∼15 mole% naphthenes. Experimental and modeling studies have been conducted in this work to assess autoignition characteristics of the GCI blend. Ignition delay times were measured in a shock tube and a rapid comparison machine over wide ranges of experimental conditions (20 and 40 bar, 640–1175 K, ϕ = 0.5, 1 and 2). Reactivity of the GCI blend was compared with experimental measurements of two surrogates: a multi-component surrogate (MCS) and a two-component primary reference fuel (PRF 77). Both surrogates capture the reactivity of the fuel quite well at high and intermediate temperatures. The MCS does a better job of emulating the fuel reactivity at low temperatures, where PRF 77 is more reactive than the GCI blend. Ignition delay times of the two surrogates are also simulated using detailed chemical kinetic models, and the simulations agree well with the experimental findings. The results of rate-of-production analyses show important role of cycloalkane chemistry in the overall autoignition behavior of the fuel at low temperatures.

已提出将低辛烷值（轻质和重质石脑油）和高辛烷值（重整）馏分燃料的混合物用于为汽油压缩点火（GCI）发动机提供动力。配制的“ GCI混合物”的研究辛烷值（RON）为77，电机辛烷值（MON）为73.9。除约64摩尔％的链烷烃组分外，共混物还包含约20摩尔％的芳族化合物和约15摩尔％的环烷烃。在这项工作中进行了实验和建模研究，以评估GCI混合物的自燃特性。点火延迟时间是在冲击管和快速比较仪中在各种实验条件（20和40 bar，640-1175 K，ϕ = 0.5、1和2）。将GCI混合物的反应性与两种替代物的实验测量结果进行了比较：一种多组分替代物（MCS）和一种两种组分的主要参考燃料（PRF 77）。两种替代物在高温和中温下都能很好地捕获燃料的反应性。MCS在模拟低温下的燃料反应性方面做得更好，PRF 77的反应性比GCI混合物高。还使用详细的化学动力学模型模拟了两种替代物的点火延迟时间，并且该模拟与实验结果非常吻合。生产率分析的结果表明，环烷烃化学在低温下燃料的整体自燃行为中起着重要作用。